Wash. Rev. Code § 35.34.150
If a public emergency which could not reasonably have been foreseen at the time of filing the preliminary budget requires the expenditure of money not provided for in the budget, and if it is not one of the emergencies specifically enumerated in RCW 35.34.140, the city or town legislative body before allowing any expenditure therefor shall adopt an ordinance stating the facts constituting the emergency and the estimated amount required to meet it and declaring that an emergency exists.
The ordinance shall not be voted on until five days have elapsed after its introduction, and for passage shall require the vote of one more than the majority of all members of the legislative body of the city or town.
Any taxpayer may appear at the meeting at which the emergency ordinance is to be voted on and be heard for or against the adoption thereof.
RCW 35.34.150